Installation Notes - USP Connectors

Wood Screw Applications – WS series continued
© Copyright 2013 USP Structural Connectors®
Joining 2 Ply 4x2 Floor Trusses
The following information pertains to the use of the USP’s WS6 Wood Screws to fasten together a two-ply 4x2 floor truss
girder, such that the induced loads are supported by both truss plies. Screw spacing and the location of each specific
screw may vary depending on the design criteria for each application, and therefore must be determined by the truss or
building designer. However, in the determination of screw locations, the following criterion shall also be considered.
These criterion are varying dependent upon how trusses are loaded as follows:
Uniform/Distributed Load
• Screws shall be installed into the top chord with a horizontal
spacing between screws of not less than 4-inches on centre and
not more than 24-inches on centre.
• A minimum end distance of 4-inches must be maintained. If
necessary, additional screws may be installed in the bottom chord.
• Centre screw vertically on 11/2˝ dimension of top chord. If
splitting occurs, it may be necessary to pre-drill the holes in
accordance with the code.
• The screws shall be installed with the headed end of the screw
on the loaded truss. If either ply is “the loaded truss”, the screws
shall be divided between the two plies, with the spacing on each
side twice the minimum indicated above.
• The screws shall not be installed through the metal truss plates,
unless approved by the truss designer and the plates are
pre-drilled, on each side to a 1/4-inch diameter. Do not drill through
the wood.
• The maximum gap between the wood members of the two
trusses shall be 1/8-inch.
• The truss designer shall design the truss members with the
capacity and capability of the screws in mind, and shall meet all
provisions of the code and ANSI/TPI.
• Individual screw locations may need to be adjusted to avoid
conflicts with connectors, problematic wood or other framing
members. Adjustments should follow the criteria described in this
section.
Concentrated/Point Load
The placement of fasteners for concentrated loading includes all
requirements of uniform loading with the additional following
criteria:
• Loads must occur over a vertical member, and the necessary
concentration of screws shall be installed in the vertical member.
• Additional screws may be installed on the top chord and
adjacent web members if necessary.
• The fasteners should be grouped as close to the concentrated
load as possible, but satisfy the same minimum spacing
indicated for uniform loading.
• In no case shall the required group of fasteners extend beyond
12-inches from the location of the concentrated load.
Uniform/Distributed Load
Applied distributed load
WS6 Wood Screws
WS6 Wood Screw
Additional
WS6 Wood Screw
if necessary
Concentrated/Point Load
12˝
max
Applied Concentrated Load
Applied Concentrated Load
12˝
max
Fasteners
Truss Members
3 1 /2˝
3 1 /2˝ 5/8˝ - 7 /8˝
Factored Shear Loads (100%) 1
USP
DF-L
S-P-F
Stock No. Ref. No. Lbs kN Lbs kN
WS6 SDS25600 672 2.99 591 2.63
1) Factored Resistance values determined in accordance
with CSA O86-09 Clause 10.11.
New products or updated product information are
designated in red font.
1 1 /2˝
Screw Detail
Typ. @ all
members
WS6 Wood Screw
1-800-328-5934 • www.USPconnectors.com 19
USP2240-131